1. Stereochemistry at C-11 and C-12 in the biosynthesis of olean-12-ene, urs-12-ene, and β-sitosterol from [5-13C,5-2H2]mevalonolactone in tissue cultures of Isodon japonicus Hara Shujiro Seo,Yutaka Tomita,Kazuo Tori,Yohko Yoshimura J. Chem. Soc. Chem. Commun. 1980 1275